Several neuropsychiatric syndromes including Alzheimer's dementia, Gilles de la Tourette's syndrome, are being studied in terms of memory function and possible pharmacological treatment. The pathophysiology and neuropharmacology of anorexia nervosa and orthostatic hypotension is also under investigation. A clinical trial of a combination of lecithin and THA (an oral cholinesterase inhibitor) in Alzheimer's dementia was not efficacious. A single dose trial of DDAVP, a vasopressin analog, in Alzheimer's dementia increases semantic memory and arousal. A study of brain dopamine and serotonin metabolism in Gilles de la Tourette's syndrome did not indicate an abnormality in these systems. Endogenous opioids are increased in CSF in underweight patients with anorexia nervosa. In orthostatic hypotension therapeutic trials with midodrine (a long-acting alpha agonist) and dihydroergotamine (an ergot veno-constricter) are underway. A trail of indomethacin in orthostatic hypotension was efficacious, and raised standing mean blood pressure an average of 37 mm Hg.